Intravascular occlusion balloon catheter

ABSTRACT

An intravascular occlusion balloon catheter having a removable hub, a profile sized to approximate a guidewire, and a means for venting air from the balloon. The removable hub and the small profile allow the occlusion balloon catheter to be used as a guidewire. The venting means allows air to be easily and reliably removed from the balloon prior to use.

FIELD OF THE INVENTION

[0001] The present invention generally relates to intravascular devicesand methods of use. In particular, the present invention relates tointravascular occlusion balloon catheters and their use to preventmigration of embolic materials during an intravascular procedure.

BACKGROUND OF THE INVENTION

[0002] Minimally invasive intravascular procedures are common in thetreatment of vascular disease. For example, intravascular restrictionsdue to atherosclerosis, restenosis, or the like may be dilated byintravascular balloon catheters or may be removed by intravascularatherectomy catheters. These intravascular procedures and the use oftheir associated devices may result in embolic particles being dislodgedas the restriction is being dilated or cut. The embolic particles maycause an embolism to form downstream of the restriction which, in turn,may compromise the flow of blood to the surrounding tissue.

[0003] To alleviate this potential risk, intravascular occlusion ballooncatheters have been developed. Such occlusion catheters typicallyinclude an elongate shaft and a distally mounted balloon. The shaft andthe balloon are insertable into a lumen of a primary catheter such as adilatation catheter or an atherectomy catheter. The occlusion balloon ispositioned distal of the treatment site and temporarily inflated toprevent embolic particles from flowing downstream as the restriction isbeing dilated or cut. After the restriction has been treated, theprimary catheter is removed over the occlusion balloon catheter. Thetreatment site proximal of the occlusion balloon is then aspiratedthrough a guide catheter. Once the embolic particles have beenaspirated, the occlusion balloon is deflated and removed from thepatient.

[0004] In order to retract the primary catheter over the occlusionballoon catheter, the occlusion catheter must be approximately two timesthe length of the guidewire lumen of the primary catheter. Dilatationcatheters are typically 70-150 cm in length, which requires theocclusion catheter to be approximately 140-300 cm or more in length. Anocclusion catheter of such length may compromise the ability of thetreating physician to manipulate the catheter and is otherwisecumbersome to handle. Accordingly, it is desirable to provide arelatively short intravascular occlusion balloon adapted for use with astandard length primary catheter. It is also desirable to provide anocclusion catheter that is simple to prepare for use.

SUMMARY OF THE INVENTION

[0005] The present invention provides an intravascular occlusion ballooncatheter having a length slightly greater than a conventional balloon oratherectomy catheter. The intravascular occlusion balloon catheterincludes, in preferred embodiments, a removable hub, a profile sized toapproximate a guidewire, and a means for venting air from the balloon.The removable hub and the small profile allow the occlusion ballooncatheter to be used as a standard length guidewire. The venting meansallows air to be easily and reliably removed from the balloon prior touse.

[0006] The venting means may comprise an annular ring disposed about thedistal end of the shaft with an intermediate tube fixedly connected tothe balloon and movably disposed about the annular ring. Theintermediate tube and the annular ring form a fluid tight seal to permitinflation and deflation of the balloon. The intermediate tube includes avent hole, wherein a vent path is opened through the tube and the venthole when the hole is positioned distal of the annular ring. The ventpath may be closed to inflate the balloon by positioning the holeproximal of the annular ring.

[0007] In one alternative embodiment, a pair of longitudinally spacedannular rings are included proximate the distal end of the shaft with atleast one hole penetrating through the shaft between the annular rings.The shaft extends distally from the more distal annular ring and theballoon is sealingly affixed at the distal end thereof. An intermediatetube is slidably mounted relative to the longitudinally spaced annularrings such that in a first position or proximal position, the vent holeis opened through the tube and a vent path is created to the exterior ofthe catheter for purging the catheter. In a second position or distalposition, the intermediate tube extends over both the proximal anddistal annular rings in sealing engagement to block the vent hole toallow inflation of the balloon during use.

[0008] Alternatively, the venting means may comprise an intermediatetube disposed between the balloon and the distal end of the shaft. Thetube includes an inflation lumen, a vent lumen, and a vent hole, with amovable plug disposed in the vent lumen. A vent path is opened throughthe vent lumen and the vent hole when the plug is positioned proximal ofthe hole. The vent path may be closed to inflate the balloon bypositioning the plug distal of the hole. A retainer may be disposed inthe vent lumen distal of the vent hole to prevent the plug from enteringthe balloon. In this embodiment, a pusher is used to move the plug froma venting configuration to an inflation configuration. The cathetershaft may include an access port proximal of the movable plug so thatthe pusher may be inserted through such port. This design eliminates theneed for the pusher to extend through the inflation lumen of the shaft.However, an alternative design includes the pusher extending within theinflation lumen to the movable plug.

[0009] The venting means may also comprise a re-sealable materialdisposed in a lumen of an intermediate tube disposed between the balloonand the distal end of the shaft. A vent path is opened when a needle isdisposed through the re-sealable material. The vent path may be closedto inflate the balloon by removing the needle from the re-sealablematerial.

[0010] The venting means may also comprise a vent lumen extendingbetween the balloon interior and a vent hole. A coaxially disposedintermediate tube or sleeve may be slidably disposed over the cathetershaft in a first position to allow venting through the vent hole. Theslidably disposed sleeve may be moved to a second, sealed, position foroccluding the vent hole to allow inflation of the balloon.

[0011] The venting means may also comprise a vent lumen extendingbetween the balloon interior and the vent hole together with a plugdimensioned for insertion into the vent lumen. The catheter can bepurged through the vent lumen, followed by plugging the vent lumen byinserting the plug. The plug may be radiopaque and may comprise aswellable polymer injected into the vent lumen.

[0012] The venting means may also comprise a vent lumen extendingbetween the balloon interior, a vent hole, and a proximally disposedplug access hole vent. A plug may be slidably disposed in the vent lumenin a first position proximal of the vent hole for purging the balloon.The plug may be moved into a second position for occluding the vent holefor inflating the balloon. The plug may be pushed distally into positionover the vent hole using a push rod inserted through the plug accesshole.

[0013] The present invention also includes a method of using anintravascular occlusion balloon catheter having a removable hub incombination with a primary intravascular catheter having a guidewirelumen. In addition, the occlusion balloon catheter may have a ventingmechanism, such that air may be vented from the balloon prior tointravascular insertion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a plan view of a distal portion of an occlusion ballooncatheter, shown in an inflated state, in accordance with one embodimentof the present invention;

[0015]FIG. 2 is a plan view of the occlusion balloon catheterillustrated in FIG. 1, but shown in a deflated venting state;

[0016]FIG. 3 is a plan view of the shaft of the occlusion ballooncatheter illustrated in FIG. 1;

[0017]FIG. 4 is a plan view of the balloon and intermediate tube of theocclusion balloon catheter illustrated in FIG. 1;

[0018]FIG. 5 is a plan view of an alternative distal portion of anocclusion balloon catheter, shown in a venting state;

[0019]FIG. 6 is a plan view of the occlusion balloon catheterillustrated in FIG. 5, but shown in an inflated state having a vent holesealed by an intermediate tubular member;

[0020]FIG. 7 is a partial longitudinal cross-sectional view of a distalportion of an occlusion balloon catheter, shown in a deflated ventingstate, and incorporating a push rod and plug arrangement accessible fromexterior of the catheter shaft;

[0021]FIG. 8 is a partial longitudinal cross-sectional view of a distalportion of the occlusion balloon catheter of FIG. 7 depicting themovable plug positioned to seal the catheter for inflation of theballoon;

[0022]FIG. 9 is a cross-sectional view of the shaft of the occlusionballoon catheter of FIG. 8 taken at line 9-9;

[0023]FIG. 10 is a cross-sectional view of the shaft of the occlusionballoon catheter of FIG. 8 taken at line 10-10;

[0024]FIG. 11 is a cross-sectional view of the shaft of the occlusionballoon catheter of FIG. 8 taken at line 11-11;

[0025]FIG. 12 is a partial longitudinal cross-sectional view of a distalportion of an occlusion balloon catheter, shown in a deflated ventingstate, in accordance with another embodiment of the present invention;

[0026]FIG. 13 is a partial longitudinal cross-sectional view of theocclusion balloon catheter illustrated in FIG. 12, but shown in aninflated state;

[0027]FIG. 14 is a partial longitudinal cross-sectional view of a distalportion of an occlusion balloon catheter, shown in a deflated state, inaccordance with yet another embodiment of the present invention;

[0028]FIG. 15 is a partial longitudinal cross-sectional view of theocclusion balloon catheter illustrated in FIG. 14, but shown in aninflated state;

[0029]FIG. 16 is a longitudinal plan view of a distal portion of anocclusion balloon catheter, shown in a deflated state, in accordancewith a further embodiment of the present invention;

[0030]FIG. 17 is a longitudinal plan view of the occlusion ballooncatheter illustrated in FIG. 16, but shown in an inflated state;

[0031]FIG. 18 is a partial longitudinal cross-sectional view of anocclusion balloon catheter having a distal purge lumen, exit port, andcoaxially disposed slidable sleeve for sealing the exit port shown in anopen position;

[0032]FIG. 19 is a partial longitudinal cross-sectional view of theocclusion balloon catheter illustrated in FIG. 18, shown in a closedposition;

[0033]FIG. 20 is a transverse, cross-sectional view through 20-20 ofFIG. 18, illustrating one set of lumen shapes;

[0034]FIG. 21 is a partial longitudinal cross-sectional view of anocclusion balloon catheter having a distal purge lumen, and exit portshown in an open configuration;

[0035]FIG. 22 is a longitudinal cross-sectional view of the occlusionballoon catheter illustrated in FIG. 21 having the distal purge lumensealed with a plug;

[0036]FIG. 23 is a partial longitudinal cross-sectional view of anocclusion balloon catheter including a distal purge lumen having aslidable proximally disposed plug, a proximal plug access port, and anintermediate disposed exit port;

[0037]FIG. 24 is a partial longitudinal cross-sectional view of theocclusion balloon catheter illustrated in FIG. 23 and having the plugblocking the exit port; and

[0038]FIG. 25 is a longitudinal cross-sectional view of a removable hubdisposed on a proximal shaft in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0039] The following detailed description should be read with referenceto the drawings in which similar elements in different drawings arenumbered the same. The drawings, which are not necessarily to scale,depict selected preferred embodiments and are not intended to limit thescope or spirit of the invention.

[0040] Refer now to FIGS. 1 and 2, which illustrate plan views of adistal portion of an occlusion balloon catheter 10 in accordance withone embodiment of the present invention. Occlusion balloon catheter 10includes an elongate shaft 12 and a distally mounted occlusion balloon14. In FIG. 1, the balloon 14 is shown in an inflated state, and in FIG.2, the balloon 14 is shown in a deflated state.

[0041] Occlusion balloon catheter 10 also includes an intermediate tube16 fixedly and sealably connected to the proximal end of the balloon 14.The intermediate tube 16 is coaxially disposed about the distal end ofthe shaft 12 and is movable relative thereto. Both the intermediate tube16 and the occlusion balloon 14 are shown as being transparent in orderto clearly illustrate the arrangement of parts at the distal portion ofthe catheter 10.

[0042] One or more annular ring(s) 18 are disposed proximate the distalend of the elongate shaft 12 to form a seal with the inside surface ofthe intermediate tube 16 during longitudinal movement or at variousfixed longitudinal portions of intermediate tube 16. Preferably, twoannular ring(s) 18 are provided to ensure a fluid-tight seal between theshaft 12 and the intermediate tube 16. With this arrangement, theballoon 14 and the intermediate tube 16 may be moved in the longitudinaldirection relative to the elongate shaft 12 while maintaining a fluidseal therebetween.

[0043] Intermediate tube 16 also includes a vent hole 22 positionedadjacent to or proximal of the annular ring(s) 18. A shaft marker 20 isprovided on the distal end of the elongate shaft 12 to indicate that thevent hole 22 is properly positioned. The vent hole 22 is sealed in thisposition to close the vent path and define an inflation path. Theinflation path is defined through the lumen 26 (not visible) of theelongate shaft 12 to the interior 28 (not visible) of the inflatableballoon 14. Accordingly, the balloon 14 may be inflated by connecting afluid source (not shown) to a removable hub 100 (illustrated in FIG. 18)connected to the proximal end of the elongate shaft 12.

[0044] The movable seal between the annular ring(s) 18 and the insidesurface of the intermediate tube 16 allows the intermediate tube 16 andthe balloon 14 rigidly connected thereto to be slid in a distaldirection such that the vent hole 22 is positioned distal of the annularring(s) 18, as illustrated in FIG. 2. With the vent hole 22 positioneddistal of the annular ring(s) 18, the catheter 10 is now ready forpurging air from the interior 26 of the catheter 10, and particularlyfrom the interior 28 of the balloon 14. Air may be purged via a ventpathway defined from the lumen of the shaft, into the interior 28 of theballoon 14, through the annular space between the intermediate tube 16and the shaft 12, up to the annular ring(s) 18, and out the vent hole22.

[0045] To vent the air from the catheter 10, the removable hub 100 (seeFIG. 25) is connected to the proximal end of the elongate shaft 12. Apressurized fluid source such as a syringe or inflation devicecontaining a suitable inflation medium such as water or saline isconnected to the removable hub 100. Fluid is injected into the catheter10 using the pressurized fluid source connected to the removable hub 100until fluid begins to emerge from the vent hole 22. In order to ensurethat the inflation medium has displaced all of the air in the balloon14, the flow of pressurized inflation medium is continued until a steadystream of liquid emerges from the vent hole 22. Preferably, a steadystream of liquid is allowed to flow from the vent hole 22 forapproximately 15 to 20 seconds. The intermediate tube 16 and the balloon14 are then slid proximally until the proximal end of the intermediatetube 16 is in alignment with the shaft marker 20. With the proximal endof the intermediate tube 16 aligned with the shaft marker 20, the venthole 22 is positioned adjacent to or proximal of the annular ring(s) 18to thereby close the vent pathway. The occlusion balloon catheter 10 isnow prepared for intravascular use.

[0046] In use, the occlusion balloon catheter 10 may be inserted before,after, or simultaneously with the primary treatment catheter (i.e., aballoon dilatation catheter or an atherectomy device). If the occlusioncatheter 10 is to be inserted after the primary catheter has beeninserted into the vascular system, or if the occlusion catheter 10 is tobe inserted at the same time as the primary catheter, it is notnecessary to initially remove the hub 100 from the proximal end of theshaft 12. If the occlusion catheter 10 is inserted into the vascularsystem prior to the primary catheter, it is necessary to initiallyremove the hub 100 such that the primary catheter may be advanced overthe occlusion catheter 10.

[0047] Regardless of order, once the occlusion balloon 14 has beeninflated in the desired vascular position, a mandrel may be insertedinto the proximal end of the elongate shaft 12 to occlude the inflationlumen 26. The mandrel, (not shown) is sized to form an interference fitwith the inside surface of the elongate shaft 12 to form a fluid tightseal and thereby occlude the inflation lumen 26. The mandrel is alsosized to be equal to or less than the profile of the catheter 10, suchthat it does not interfere with the advancement or removal of theprimary catheter. Once the proximal end of the inflation lumen 26 hasbeen occluded by the mandrel, the hub 100 may be removed from theproximal end of the shaft 12.

[0048] After treatment, the primary catheter may be removed from theocclusion catheter 10, which is held in place by the occlusion balloon14 engaging the inside wall of the vessel. The treatment site may thenbe aspirated in the conventional manner using a guide catheter throughwhich both the primary catheter and the occlusion catheter 10 have beeninserted. After aspiration, the mandrel may be removed from the shaft 12to deflate the balloon 14. After deflation of the balloon 14, theocclusion catheter 10 may be removed from the patient's vascular system.

[0049] The occlusion balloon catheter 10 may have a length slightlygreater than the primary catheter and an outside profile approximating aconventional guidewire, such that the catheter 10 may be inserted intothe guidewire lumen of the primary catheter. For example, the occlusionballoon catheter 10 may have a length of approximately 150 cm and anoutside profile of approximately 0.035 inches when in a deflated state.Those skilled in the art will recognize that the dimensions of thecatheter 10 may be modified to be compatible with a wide variety ofprimary catheters depending on the length and guidewire lumen diameterof the chosen primary catheter.

[0050]FIGS. 3 and 4 are detailed views of the shaft 12, the intermediatetube 16, and the balloon 14 of the occlusion balloon catheter 10illustrated in FIGS. 1 and 2. The elongate shaft 12 may be approximately150 cm long and may be formed of a suitable medical grade material toapproximate the characteristics of a similarly dimensioned guidewire.The annular ring(s) 18 may be formed of a medical grade adhesive, suchas a cyanolacrolate available under the tradename LOCTITE Part No. 3301.The annular ring(s) 18 may be spaced about 0.260 inches apart, with thedistal annular ring 18 spaced about 0.668 inches from the distal end ofthe shaft 12. The shaft marker 20 may be located approximately 0.979inches from the distal end of the shaft 12, but may be varied dependingon the length of the intermediate tube 16 and the position of the venthole 22.

[0051] The intermediate tube 16 may be formed of a suitable medicalgrade material having a length of approximately 1.30 inches. Theproximal end 24 of the intermediate tube 16 may be flared to provideeasy insertion of the shaft 12 therein. The vent hole 22 may bepositioned 0.300 inches from the proximal end of the intermediate tube16 and may have an inside diameter of approximately 0.016 inches.

[0052] Referring now to FIGS. 5 and 6, plan views of an alternativeportion of an occlusion balloon catheter 10 similar to that which isdepicted in FIGS. 1 and 2, are illustrated. Except as described herein,the structure and use of occlusion balloon catheter 10 of FIGS. 5 and 6is the same as catheter 10 described with reference to FIGS. 1-4.Occlusion balloon catheter 10 includes an elongate shaft 12 which has aballoon 14 fixedly secured proximate its distal end and extending distalthereto. The lumen 13 of shaft 12 is utilized for injecting inflationfluid into the balloon 14.

[0053] The shaft 12 includes at least two annular rings 18 disposedproximal of the balloon 14 and extending around the circumference of theshaft 12. The annular rings 18 are spaced longitudinally, and at leastone vent hole 22 penetrates from outside the shaft 12 into the lumen 13.

[0054] An intermediate tube 16 is coaxially disposed in longitudinallymovable relation to the shaft 12 proximate the annular rings 18. Asdepicted in FIG. 5, the intermediate tube 16 may be located in a firstlongitudinal position such that vent hole 22 is open to the outside ofthe shaft to allow venting of air from within. In this way, the shaft 12may be purged before intravascular use. Further, as depicted in FIG. 6,the intermediate tube 16 may be moved to a second longitudinal positionsuch that the interior surface of the intermediate tube 16 engages bothannular rings in sealing arrangement. This arrangement blocks the venthole 22 and allows inflation of balloon 14 through lumen 13 of shaft 12.

[0055] Refer now to FIGS. 7 and 8 which illustrate a partiallongitudinal cross-sectional view of a distal portion of an occlusionballoon catheter 30 in accordance with an alternative embodiment of thepresent invention. Except as described herein, the structure and use ofocclusion balloon catheter 30 is the same as the occlusion ballooncatheter 10 described with reference to FIGS. 1-6. The depictedembodiment includes an elongate shaft 12 and a balloon 14 mounted on thedistal end of the shaft 12. A distal portion of the shaft 12 includes anintermediate tube or tubular portion 31 of shaft 12 which is disposedbetween the proximal portion of elongate shaft 12 and the balloon 14. Inalternative embodiments of the present invention, the intermediate tubeor tubular portion 31 may be a separate tube which is connected to thedistal end of the proximal portion of the elongate shaft 12, or it maybe an integral portion which is formed at the time of manufacture of theelongate shaft 12. In a preferred embodiment, the intermediate tube 31is thermally bonded to the distal end of the proximal portion ofelongate shaft 12.

[0056] Intermediate tube 31 includes an inflation lumen 32, whichprovides fluid communication between the inflation lumen 26 of the shaft12 and the interior 28 of the balloon 14. The intermediate tube 31 alsoincludes a vent lumen 34 which includes a vent hole 36 opening to theexterior of the intermediate tube 31. As illustrated in thecross-sections of FIGS. 9-11, intermediate tube 31 is preferably adual-lumen extrusion having side-by-side lumens 32 and 34. It is,however, recognized that intermediate tube 31 may be formed by othersuitable means, such as two separate extruded tubes arrangedside-by-side and connected by adhesive, or the like.

[0057] The embodiment of FIGS. 7 and 8 further includes a pusher or pushrod 33 which is insertable through a side access port into the ventlumen 34 of intermediate tube 31. A movable plug 38 is disposed in thevent lumen 34 to provide a fluid-tight seal when positioned distal ofthe vent hole 36 as depicted in FIG. 8. The push rod or pusher 33 isutilized to move the movable plug 38 from a first position which isproximal of the vent hole 36 to a position distal of the vent hole 36 insealing arrangement with the lumen wall 34. In the first position, airmay be purged from the shaft 12 and balloon 14, while in the secondposition, the balloon may be inflated during intravascular use. Aretainer 40 disposed in the vent lumen 34 provides a reduction in thesize of lumen 34 and prevents the removable plug 38 from entering theinterior 28 of the balloon 14, thereby retaining the removal of plug 38in the vent lumen 34. Although the embodiment of FIGS. 7 and 8 depict aseparate vent hole 36 and access port 35 for the pusher 33, it isrecognized that a single port could provide both functions provided themovable plug 38 is sized for sealing engagement with the lumen wall at areduced diameter longitudinal location, while allowing flow of air andfluid during purging when positioned proximally in a larger diameterportion of the lumen which allows flow around the movable plug.

[0058] Refer now to FIGS. 12 and 13, which illustrate longitudinalcross-sectional views of a distal portion of an occlusion ballooncatheter 30 in accordance with another embodiment of the presentinvention. Except as described herein, the structure and use ofocclusion balloon catheter 30 is the same as occlusion catheter 10described with reference to FIGS. 1-6 or occlusion catheter 30 describedwith reference to FIGS. 7-8. Occlusion balloon catheter 30 includes anintermediate tube or tubular portion 31 disposed between the elongateshaft 12 and the balloon 14 which may be a separate tubular member orformed integral with shaft 12. The proximal end of the intermediate tube31 is connected to the distal end of the elongate shaft 12, and theproximal end of the balloon 14 is connected to the distal end of theintermediate tube 31.

[0059] The intermediate tube 31 includes an inflation lumen 32, whichprovides fluid communication between the inflation lumen 26 of the shaft12 and the interior 28 of the balloon 14. The intermediate tube 31 alsoincludes a vent lumen 34 and a vent hole 36. As illustrated,intermediate tube 31 is a dual-lumen extrusion having side-by-sidelumens 32 and 34. Those skilled in the art, however, will recognize thatthe intermediate tube 31 may be formed by other suitable means, such astwo separately extruded tubes arranged side-by-side and connected byadhesive, or the like.

[0060] A movable plug 38 is disposed in the vent lumen 34 to provide afluid-tight seal therein. The intermediate tube also includes a retainer40 disposed in the vent lumen 34 adjacent the distal end of the tube 31.Retainer 40 prevents the removable plug 38 from entering the interior 28of the balloon 14, thereby maintaining the removable plug 38 in the ventlumen 34. As depicted, a pusher or push rod 33 may be disposed with theshaft lumen 26 to contact and reposition removable plug 38 as necessarybetween a purge position and a balloon inflation position.

[0061] With the movable plug 38 positioned proximal of the vent hole 36,a vent pathway is defined extending from the interior 28 of the balloon14, through the vent lumen 34 of intermediate tube 31, and out the venthole 36. In this manner, air in the catheter 30, and in particular theinterior 28 of the balloon 14, may be purged or vented as describedpreviously. Once the air has been displaced from the interior of thecatheter 30, the plug 38 may be advanced in the distal direction throughthe vent lumen 34. When the movable plug 38 is in a position distal ofthe vent hole 36, the vent pathway is sealed.

[0062] The movable plug 38 may be advanced distal of the vent hole 36 byutilizing the push rod 33 inserted into the proximal end of the catheter30, through the inflation lumen 26, and into the vent lumen 34 of theintermediate tube 31. Such a push rod should be dimensioned at thedistal end thereof to be insertable into the vent lumen 34. Once themovable plug 38 is in the desired position, the push rod may be removed.The occlusion catheter 30 is then ready for use.

[0063] Refer now to FIGS. 14 and 15, which illustrate a longitudinalcross-sectional view of a distal portion of an occlusion ballooncatheter 50 in accordance with yet another embodiment of the presentinvention. Except as described herein, the structure and use ofocclusion catheter 50 is the same as occlusion catheter 10 discussedwith reference to FIGS. 1-6 and the occlusion catheter 30 discussed withreference to FIGS. 7-13. Occlusion balloon catheter 50 includes anintermediate tube 51 disposed between the elongate shaft 12 and theinflatable balloon 14. The intermediate tube 51 includes an inflationlumen 52 fluidly connecting the inflation lumen 26 of the shaft 12 tothe interior 28 of the balloon 14.

[0064] The intermediate tube 51 also includes a vent lumen 54 having aresealable material 58 disposed therein. The resealable material 58,such as a medical grade silicone, may be pierced by a needle 60 or othersimilar structure to define a vent pathway from the interior of theballoon 28. Specifically, a vent pathway is defined from the interior 28of the balloon 14 through the lumen 62 of the needle 60.

[0065] With this arrangement, air in the catheter 50, and in particularthe interior 28 of the balloon 14, may be vented or purged as discussedpreviously. Once air has been removed from the catheter 50, the needle60 may be slowly removed from the resealable material 58. As the needle60 is removed from the resealable material 58, the vent lumen 54 isresealed, thus closing the vent pathway. Preferably, the needle 60 ispartially withdrawn from the resealable material 58, and the resealablematerial is allowed to relax for approximately 15 seconds to fill thevoid left by the needle 60. If, after complete removal of the needle 60,fluid continues to flow through the resealable material 58, the needle60 may be reinserted and withdrawn slowly again. After removal of theneedle 60 without leakage, the occlusion catheter 50 is ready for use.

[0066] Refer now to FIGS. 16 and 17, which illustrate longitudinalcross-sectional views of a distal portion of occlusion balloon catheter70 in accordance with a further embodiment of the present invention.Except as described herein, occlusion balloon catheter 70 may be thesame in structure and use as occlusion catheter 10 described withreference to FIGS. 1-6 and occlusion catheter 30 or 50 described withreference to FIGS. 7-13 and FIGS. 14-15, respectively. Occlusion ballooncatheter 70 includes an intermediate tube 71 disposed between theelongate shaft 12 and the occlusion balloon 14. Intermediate tube 71includes an inner tube 76 disposed inside an outer tube 74. The innertube 76 of the intermediate tube 71 includes an inflation lumen 72providing a fluid connection between the inflation lumen 26 of the shaft12 and the interior 28 of the balloon 14.

[0067] A resealable material 78 is disposed in the annular lumen definedbetween the inner tube 76 and the outer tube 74. The resealable material78 operates essentially the same as the resealable material 58 describedwith reference to FIGS. 14 and 15. However, the needle 60 is insertedlaterally through the intermediate tube 71, piercing the outer tube 74and the inner tube 76. The resealable material 78 serves to seal thevoid defined by the needle 60 when inserted into the intermediate tube71.

[0068] With this arrangement, a vent pathway is defined from theinterior 28 of the balloon 14, through the lumen 72 of the intermediatetube 71, and into the lumen 62 of the needle 60. Once air has beenpurged from the catheter 70, and in particular the interior 28 of theballoon 14, the needle 60 may be slowly removed from the intermediatetube 71, such that the resealable material 78 is allowed to fill thevoid left by the needle 60 and thereby close the vent pathway. Afterremoval of the needle 60 and closure of the vent pathway, the occlusioncatheter 70 is ready for use.

[0069] Refer now to FIGS. 18, 19, and 20, which illustrate a distalportion of an occlusion catheter 120 in accordance with a furtherembodiment of the present invention. Except as noted herein, occlusionballoon catheter 120 is the same in structure and use as the occlusioncatheters previously described. Occlusion balloon catheter 120 includesan intermediate tube or sleeve 122 coaxially disposed about cathetershaft 12. Intermediate tube 122 is illustrated in a first, open positionin FIG. 18. Inflation lumen 26 narrows to a distal inflation lumenportion 126 defined by distal inflation tube walls 128 terminating in adistal inflation tube port 130 leading into balloon interior 28. Ballooninterior 28 is in fluid communication with a vent lumen 132 definedbetween inflation tube walls 128 and a vent tube wall 134. Vent lumen132 curves from a longitudinal orientation to an angle relative to thewall of shaft 12, and terminates proximally in a vent hole 136. A firstseal or gasket 138 is disposed distal of vent hole 136. A second seal orgasket 140 is disposed proximal of vent hole 136. Seals 138 and 140 arepreferably annular seals which surround shaft 12. Seals 138 and 140 canbe formed of materials such as silicone rubber and can be formed asO-rings in some embodiments.

[0070]FIG. 19 illustrates occlusion catheter 120 in a second, closed andsealed position. Intermediate tube or sleeve 122 is illustrated in asealed position, having the inner wall of sleeve 122 in contact withboth distal seals 138 and proximal seals 140, thereby forming a sealover vent hole 136. FIG. 20 is a transverse cross-sectional view ofshaft 12 through a portion having both lumen 126 and vent lumen 132. Inone embodiment, the dual lumen portion is formed as a single extrusion.In another embodiment, the dual lumen portion is formed by necking downlumen 26 to 126 and securing a second vent tube having vent lumen 132 tothe top of the necked down shaft.

[0071] In use, occlusion catheter 120 can be put into the first, openposition illustrated in FIG. 18 by having sleeve 122 slid into theproximal position as illustrated. In another embodiment, not requiringillustration, sleeve 122 can be disposed distally of vent hole 136 whilein the open position, rather than proximally of vent hole 136. Liquidfluid can be injected into lumen 26, thereby flushing balloon interior28, flowing through vent lumen 132, and exiting through vent hole 136.After balloon interior 28 has been flushed for a suitable period oftime, and most or all of any gaseous fluid originally within ballooninterior 28 purged, sleeve 122 can be slid into the second positionillustrated in FIG. 19. Once in the closed position, inflation fluid canbe supplied to inflate balloon 14.

[0072] Referring now to FIGS. 21 and 22, an occlusion catheter 142 isillustrated including a proximal tube 144 secured to an intermediatedisposed tube 146, which is in turn secured to a distally disposed tube148 having a distal opening 149. In a preferred embodiment, proximaltube 144 is formed of a polymeric material, intermediate tube 146 isformed of hypotube, and distal tube 148 is formed of a polymericmaterial. In one embodiment, tubes 144, 146, and 148 are formed ofprogressively more flexible material. A second, vent tube 152 isillustrated secured to distal tube 148. Vent tube 152 includes a ventlumen 150 therein. Vent lumen 150 terminates proximally in a vent hole154. In FIG. 21, vent hole 154 has an inner diameter slightly less thanthe inner diameter of lumen 150. While in the open position illustratedin FIG. 21, fluid can be forced through lumen 26, thereby flushingballoon interior 28, and exiting through vent lumen 150 and vent hole154.

[0073] Referring now to FIG. 22, occlusion catheter 142 is illustratedin a closed or sealed position. A sealing plug 156 is illustrated,occluding vent lumen 150. In a preferred embodiment, sealing plug 156includes a radiopaque material so as to be visible under fluoroscopy.Plug 156 can be formed of an elastic material such as medical gradesilicon rubber. In an alternate embodiment, plug 156 is formed in placewith a rapidly curing polymeric material injected into vent lumen 150.Plug 156 can be inserted in place using a mandrel when the purging ofballoon interior 28 is complete. With plug 156 in place, occlusiondevice balloon 14 can be inflated as illustrated in FIG. 22.

[0074] Referring now to FIGS. 23 and 24, a distal portion of anocclusion device 160 is illustrated having features similar to device142 illustrated in FIGS. 21 and 22. Occlusion device 160 includes a venttube 168 having a proximal plug access port 164 and an intermediatedisposed vent hole 162 in the side wall of vent tube 168. FIG. 23illustrates device 160 in open position, allowing purge fluid to flowthrough lumen 26, into balloon interior 28, through vent tube 168, andout vent hole 162. In the open position, a slidable plug 166 is disposedin vent tube 168 proximal of vent hole 162. FIG. 24 illustrates device160 in a closed or sealed position. In the sealed position, plug 166 hasbeen slid distally so as to occlude vent hole 162. Plug 166 can bepushed distally from the plug open position by inserting a push rodthrough plug access hole 164.

[0075] Refer now to FIG. 25, which illustrates a longitudinalcross-sectional view of a removable hub 100 for use in combination withany of the catheters 10, 30, 50, and 70 described herein. Removable hub100 is releasably secured to the proximal end of the shaft 12 tofacilitate connection to a fluid source (not shown), such as afluid-filled syringe or an inflation device. As illustrated, removablehub 100 utilizes a compression fitting, but those skilled in the artwill recognize that other suitable mechanisms may be utilized to providea fluid-tight, removable mechanical connection to the proximal end ofthe shaft 12.

[0076] Removable hub 100 includes a proximal portion 102 and a distalportion 104 connected by threaded portions 106. Proximal portion 102 maybe rotated relative to distal portion 104 to compress or release anO-ring 110 disposed between the proximal portion 102 and the distalportion 104. When compressed, the O-ring 110 forms a fluid-tight sealwith the elongate shaft 12. When released, the O-ring is radiallydisplaced from the shaft 12, such that the hub 100 may be removedtherefrom. The elongate shaft 12 may include a retainer ring 13 toassist in the mechanical engagement between the removable hub 100 andthe shaft 12. The proximal end 102 of the hub 100 includes a standardfitting 108 for connection to a fluid source. The removable hub 100 maybe used as discussed with reference to FIGS. 1-4.

[0077] Those skilled in the art will recognize that the presentinvention may be manifested in a wide variety of forms other than thespecific embodiments contemplated and described herein. Accordingly,departures in form and detail may be made without departing from thescope or spirit of the present invention as described in the appendedclaims.

[0078] Numerous advantages of the invention covered by this documenthave been set forth in the foregoing description. It will be understood,however, that this disclosure is, in many respects, only illustrative.Changes may be made in details, particularly in matters of shape, size,and arrangement of parts, without exceeding the scope of the invention.The invention's scope is, of course, defined in the language in whichthe appended claims are expressed.

What is claimed is:
 1. An intravascular occlusion balloon catheter,comprising: an elongate shaft having a proximal end and a distal end; aremovable hub connected to the proximal end of the shaft; an inflatableocclusion balloon connected to the distal end of the shaft; and meansfor venting air from the balloon, the means disposed proximate thedistal end of the shaft.
 2. An intravascular occlusion balloon catheteras in claim 1, wherein the venting means comprises: an annular ringdisposed about the distal end of the shaft; and an intermediate tubefixedly connected to the balloon and movably disposed about the annularring, the intermediate tube and the annular forming a seal, theintermediate tube having a vent hole, wherein a vent path is openedthrough the intermediate tube and the vent hole when the hole ispositioned distal of the annular ring, and the vent path is closed whenthe hole is positioned proximal of the annular ring.
 3. An intravascularocclusion balloon catheter as in claim 1, wherein the venting meanscomprises: an intermediate tube disposed between the balloon and thedistal end of the shaft, the tube having an inflation lumen, a ventlumen and a vent hole; and a movable plug disposed in the vent lumen,wherein a vent path is opened through the vent lumen and the vent holewhen the plug is positioned proximal of the hole, and the vent path isclosed when the plug is positioned distal of the hole.
 4. Anintravascular occlusion balloon catheter as in claim 1, wherein theventing means further comprises a retainer disposed in the vent lumendistal of the vent hole to prevent the plug from entering the balloon.5. An intravascular occlusion balloon catheter as in claim 1, whereinthe venting means comprises: an intermediate tube disposed between theballoon and the distal end of the shaft, the tube having an inflationlumen and a vent lumen; and a re-sealable material disposed in the ventlumen, wherein a vent path is opened when a needle is disposed throughthe re-sealable material, and the vent path is closed when the needle isremoved from the re-sealable material.
 6. An intravascular occlusionballoon catheter as in claim 1, wherein the intermediate tube comprisesa side-by-side dual lumen tube.
 7. An intravascular occlusion ballooncatheter as in claim 1, wherein the intermediate tube comprises an innertube coaxially disposed in an outer tube and the vent lumen comprises anannular lumen therebetween.
 8. An intravascular occlusion ballooncatheter as in claim 1, wherein the venting means comprises: a ventlumen extending from the balloon to a vent port; and a sleeve slidablyand coaxially disposed near the shaft distal end, the sleeve having afirst position for occluding the vent port and a second position forallowing airflow from the vent port.
 9. An intravascular occlusionballoon catheter as in claim 8, wherein the sleeve has a length, furthercomprising a first seal disposed proximal of the vent port and a secondseal disposed distal of the vent port while the sleeve is in the firstposition, the first and second seals disposed a distance apart less thanthe sleeve length, the first and second seals having a heightsufficiently small to fit between the sleeve and the shaft in the firstposition.
 10. An intravascular occlusion balloon catheter as in claim 8,further comprising: a vent lumen extending between the balloon and afirst port disposed proximally of the balloon; and a plug dimensionedfor disposition within, and occlusion of, the vent lumen.
 11. A distalocclusion device as recited in claim 10, wherein the plug issubstantially radiopaque.
 12. A distal occlusion device as recited inclaim 10, wherein the vent lumen has a second port disposed between theballoon and the first port, wherein the plug has a length to fitproximally of the second port within the second lumen for allowing flowfrom the balloon through the second port, and wherein the plug has alength sufficient to occlude the second port.
 13. An intravascularocclusion balloon catheter, comprising: an elongate shaft having aproximal end and a distal end; a removable hub connected to the proximalend of the shaft; an inflatable occlusion balloon connected to thedistal end of the shaft, the balloon having an interior; and a ventpathway disposed on the distal end of the shaft, the vent pathway influid communication with the interior of the balloon for venting airfrom the balloon.
 14. An intravascular occlusion balloon catheter as inclaim 13, further comprising: an annular ring disposed about the distalend of the shaft; and an intermediate tube fixedly connected to theballoon and movably disposed about the annular ring, the intermediatetube forming a seal with the annular ring, the intermediate tube havinga vent hole therein, wherein the vent pathway is defined from theinterior of the balloon, between the intermediate tube and the shaft tothe annular ring, and through the vent hole.
 15. An intravascularocclusion balloon catheter as in claim 13, further comprising: anintermediate tube disposed between the balloon and the distal end of theshaft, the tube having an inflation lumen, a vent lumen and a vent hole;and a movable plug disposed in the vent lumen, wherein the vent path isdefined from the interior of the balloon, through the vent lumen to themovable plug, and through the vent hole.
 16. An intravascular occlusionballoon catheter as in claim 10, further comprising a retainer disposedin the vent lumen distal of the vent hole to prevent the plug fromentering the interior of the balloon.
 17. An intravascular occlusionballoon catheter as in claim 13, further comprising: an intermediatetube disposed between the balloon and the distal end of the shaft, thetube having an inflation lumen and a vent lumen; and a re-sealablematerial disposed in the vent lumen, wherein the vent path is definedfrom the interior of the balloon and through a removable needle disposedin the re-sealable material.
 18. A distal occlusion device comprising: atubular shaft having a proximal end, a distal region, an exterior, andan exterior wall; an inflatable device disposed near the shaft distalregion and having an interior; a first lumen extending through the shaftand being in fluid communication with the inflatable device interior; asecond lumen extending between the inflatable device interior and afirst port disposed proximally of the inflation device; and a plugdimensioned for disposition within, and occlusion of, the second lumen.19. A distal occlusion device as recited in claim 18, wherein the plugis a formed of an elastomeric material.
 20. A distal occlusion device asrecited in claim 18, wherein the plug is formed in place in the secondlumen by injecting a swellable polymeric material into the second lumen.21. A distal occlusion device as recited in claim 18, wherein the plugis substantially radiopaque.
 22. A distal occlusion device as recited inclaim 18, wherein the second lumen has a second port disposed betweenthe inflation device and the first port, wherein the plug has a lengthto fit proximally of the second port within the second lumen forallowing flow from the inflation device interior through the secondport, and wherein the plug has a length sufficient to occlude the secondport.
 23. A method of using an intravascular occlusion balloon catheterin combination with a primary intravascular catheter having a guidewirelumen sized to accommodate a guidewire therein, wherein the occlusionballoon catheter comprises an elongate shaft having an inflation lumen,a proximal end and a distal end, a removable hub connected to theproximal end of the shaft, and an inflatable occlusion balloon connectedto the distal end of the shaft, the method comprising the steps of:positioning the occlusion catheter in the guidewire lumen of the primarycatheter; inflating the balloon of the occlusion catheter; occluding theinflation lumen at the proximal end of the shaft of the occlusioncatheter; removing the hub from the shaft of the occlusion ballooncatheter; and removing the primary catheter from the occlusion ballooncatheter such that the occlusion balloon catheter is disposed in theguidewire lumen of the primary catheter.
 24. A method of using anintravascular occlusion balloon catheter as in claim 23, wherein theocclusion balloon catheter further includes a means for venting air fromthe balloon, the means disposed on the distal end of the shaft, themethod further comprising the step of venting air from the balloon priorto intravascular insertion.